Mechanically activated crystallization of phase pure nanocrystalline forsterite powders

Abstract

Pure nanocrystalline forsterite was successfully synthesized via a mechanical activation route assisted with heat treatment. X-ray diffraction (XRD), scanning electron microscopy (SEM) and simultaneous thermal analysis (STA) techniques were utilized to characterize the prepared powders. Results showed that pure nanocrystalline forsterite could be fabricated completely by 10 h of mechanical activation and post-heat treatment at 1000–1200 °C for 1 h. By 10 h mechanical activation, the initial temperature of forsterite crystallization was reduced to about 820 °C. The obtained nanocrystalline forsterite powder had crystallite size about 57 nm according to Williamson-hall approach and particle sizes smaller than 1000 nm. XRD patterns showed that pure forsterite could not be obtained by mechanical activation process alone and that enstatite could be fabricated by increasing the time of milling. Liberation of CO 2 gas increased the rate of forsterite formation by increasing contact surface between grains.